Study objectives: A recent trend in increasing rates of severe maternal morbidity and mortality despite quality improvements has been noted. The goal of this study is to estimate the national prevalence of obstructive sleep apnea (OSA) in pregnant women and examine associations between OSA and pregnancy-related morbidities, including in-hospital maternal mortality.
Design: A retrospective, cross-sectional analysis.
Setting: A nationally representative sample of maternal hospital discharges from 1998-2009.
Patients or participants: The analytic sample included 55,781,965 pregnancy-related inpatient hospital discharges.
Measurements and results: The Nationwide Inpatient Sample (NIS) database was used to identify hospital stays for women who were pregnant or gave birth. Among these women, we determined length of hospital stay, in-hospital mortality, and used International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes to identify OSA and other outcome measures. Multivariable logistic regression modeling was used to calculate adjusted odds ratios (OR) and 95% confidence intervals (CI) for the associations between OSA and each outcome. The overall rate of OSA was 3.0 per 10,000; however, the rate climbed substantially from 0.7 in 1998 to 7.3 in 2009, with an average annual increase of 24%. After controlling for obesity and other potential confounders, OSA was associated with increased odds of pregnancy-related morbidities including preeclampsia (OR, 2.5; 95% CI, 2.2-2.9), eclampsia (OR, 5.4; 95% CI, 3.3-8.9), cardiomyopathy (OR, 9.0; 95% CI, 7.5-10.9), and pulmonary embolism (OR, 4.5; 95% CI, 2.3-8.9). Women with OSA experienced a more than fivefold increased odds of in-hospital mortality (95% CI, 2.4-11.5). The adverse effects of OSA on selected outcomes were exacerbated by obesity.
Conclusions: Obstructive sleep apnea is associated with severe maternal morbidity, cardiovascular morbidity, and in-hospital death. Targeted interventions may improve pregnancy outcomes in this group.
Keywords: maternal mortality; obstructive sleep apnea; preeclampsia; pregnancy; pulmonary embolus.